1. Field of the Invention
The present invention relates to a printed circuit board and to a method of manufacturing the same.
2. Description of the Prior Art
So far, as printed circuit boards, there have been resin printed circuit boards having at least one circuit layer and through holes provided on a resin board.
As the compactization of electronic systems progresses, however, the density of mounting various components on the printed circuit board is increasing, and a greater number of components are being mounted on the printed circuit board. Since the resin printed circuit board has a low flexual rigidity, this allows the printed circuit board, to become easily warped. Thus in many cases it is impossible to insert a printed circuit board into the electronic system, or, even if it is possible to insert, the inserted printed circuit board may come in touch with the adjacent printed circuit boards, seriously affecting the whole circuit system. Also, as the components mounting density of the resin printed circuit board increases, the heat generated from those mounted components may increase, and an insufficient heat radiating ability of the resin printed circuit board permits the temperature of the resin printed circuit board and its adjacent area to rise. This invites a functional degrading of mounted components and is a serious problem at the moment. To avoid this kind of trouble, it has suggested that heat radiating fins may be attached to the mounted components, but this has a drawback in making the mounted components costly. In addition, the poor shielding effect of the resin printed circuit board makes it impossible to prevent noise.